Process of manufacturing water-gas



W. W. ODELL.

PROCESS OF MANUFACTURING WATER GAS. APPLICATION FILED NOV-7,1918.

1 ,379,038. Patented May 24, 1921.

'1 i l I l l I I I I I I UNITED STATES PATENT OFFICE.

WILLIAM WALLACE ODEIlL, OF URBANA, ILiIINOIS- PROCESS or MANUFACTURINGWATER-GAS.RE|SSUED Specification of Letters Patent.

Patented May 24, 1921.

Application filed November 7, 1918. Serial No. 261,567.

of the United States, residing at Urbana, in the county of Champaign andState of Illinois, have invented new and useful Im Erovements inProcesses of Making Wateras. This invention relates to the manufacturein a generatorby means of an air blast, after which the gas ismanufactured, chiefly,

by passing steam either up or down through the incandescent fuel, butwith improvements in the process consisting in admitting some air withthe steamduring the steam runs, and under certain specified conditionsadmitting steam with the air during blasting. The objects of theinvention are, while 7 usin any of the aforesaid fuels:

(1% To maintain a more uniform and steady heat in the generator and atthe same time a longer gas making period.

(2) To maintain control over the temperatures in carbureter andsuperheater. (3) To avoid the waste due to burning gases outside thewater gas set by burning them in the carbureter and superheaterr greaterper cent. of the fuel in the generator.

(9) To prevent the caking and arching of the fuel in generator which isa'troublesome feature in ordinary operatlon of a Water gas set usingbituminous fuel.

In obtaining these results I am taking advantage of the peculiarproperties of bituminous fuels, and of the present day standards forcity gas, which call for lower heating' value and lower candlepower'than ever before.

As far as I am aware this process is taking further distinguished fromother processes or from a-combination of a water gas and a producer gasprocess, 1st. In that it allows a greater percentage of up runs to bemade,

due to the better control of the temperature 1n the generator, therebypermitting the saving ofthe rich hydro-carbons and illuminants from thevolatile matter of the fuel 1n the top portion of the fuel bed. (Thesehydrocarbons are cracked to a great extent when forced down through thefire as with down runs). 2nd. The quantity of steam admltted during airblasting is dependent on the temperatures in the carbureter andsuperheater, and on the volume of smoke produced during blasting. Thegas produced during blastingis entirely consumed withln the water gasset and is not passed Into a gas holder. 3rd. That definite quant1t1esof auxiliary air and steam are used, and said quantities are underoperators ab.- solute control and are changed by him wheneverindications call for a change. 4th. As far as I am aware this processdiffers further from other processes in that one of the'uses of theauxiliary steam,'-the steam admitted during the air blasting,-is to increase the volume of high temperature fuel in the generator bypreventing the fuel on grates from becoming excessively hot,therebypermitting the use of a greater amount of air blast. Thefollowing chemical react1ons will help to explain the last statement:

51) C|O =CO exothermic reaction.

2) 2C+O =2CO exothermic reaction.

(3 CO,+C:2CO endothermic reaction. -(4 I-I,,O+C=CO+H endothermicreaction.

The first three reactions or equivalentare place during the ordinaryair'blasting 0 a water gas generator. The zone of complete combustion,as in reaction #1, is invariably at the bottom of the generator, and theexcessively high heats are, in common practice formed or created in thiszone. In my process, on admitting-auxiliary steam 'with the air,reaction #4 takes place, and it takes-place at the overheated part ofthe fire, the zone directly above the grates. This cooling action. inthe overheated part of the fire permits the heating of a larger zone tothe most desirable temperature, which is accomplished by using moreblast and by turning off the auxiliary steam before the end of the blastperiod. It will .be seen that as soon as fire is hot enough above theusual I hot zone, the turning off'of the auxiliary steam permits thefuel directly above grates to become hot very quickly, particularly withthe increased amount of air blast as mentioned. Thus an increased volumeof incandescent fuel is obtained.

In manufacturing Water gas by the standard method now in use, (by theLowe process) it has been shown that the following at K, and L is theoff-take valve.

To operate this machine according to my process air is first blasted upthrough fuel bed by opening valve S on air line E. When fuel bed X isheated to a sufficiently high temperature the air is shut off at valveS, and water gas is produced by admitting steam beneath the gratesthrough up run line F, by opening valve T. A little air is admittedsimultaneously through auxiliary air line B, during this steam run.During this run the valve L is closed and valve J is open. This steamwith the small with the common air control valve at difficulties areencountered when bituminous amount of air forces its way up through thefuel is used as generator fuel: Heats in the fuel bed and by chemicalcombination pro.- generatorcan not be maintained high duces gas. The (COcarbon dioxid enough to make water gas for more than a formed from thecombustion of the auxilbrief period without reblasting generator. iaryair is reconverted to (CO) carbon mon- On attempting to blast the heatsup in the oxid by the incandescent fuel (according to generator by anincreased amount of blast, reaction 3 supra) and hence the onlydilsomuch combustible gas is produced that uent of the finished gas is thenitrogen it can not all be burned in the carbureter or of said air. Nowthis is partly compensated superheater without overheating them, and forby the increase inamount of volatile if it is burned at the stackendangers meltproducts from the bituminous fuel, and ing of the stackand causes a waste of fuel. further compensated for since the hotter Thebig per cent. of tarry matter and volafire now obtainin tile matter fromthe coal produces a heavy carbon dioxid (C which is ever presentvoluminous smoke which is emitted at the in water gas; forming ingreater per cents. stack, causing a nuisance. The volume of as the fueltemperature decreases. Since gas produced, using bituminous fuel in gen-CO is the most undesirable inert in come'rator, is considerably lowerthan that probustible gas air should not be used with the duced usinggood coke as fuel and under steam so long as to increase the ercentagethe same conditions. The fuel used per of this undesirable element.After this reduces the amount of 1,000cubic feet of gas made isconsiderably steam run (up run) the steam valve T' and Clinker is theauxiliary air valve Q are closed and formed to an excessive degree whenbitumithe fuel is again blasted from beneath grates nous fuel is used ingenerator and blasted to by opening the valve S in air blast line. thenecessary temperatures for water gas pro- A small amount of steam issimultaneously duction. admitted through the auxiliary steam line Thefigure of the drawing represents a V by opening valve W. This produces acommon type water gas generator equipped richer blast gas (shown inreaction #4 to manufacture gas by my process using bisupra) which iscompletely burned in the tuminous or other high volatile fuel. Incarbureter and superheater with the elimithe figure, A represents agenerator, with 'nation of smoke and tarry matter which grates B, andfire cleaning door C, and ash pit would otherwise be in evidence atstack. door D. The charging door is shown at H. This auxiliary steam isnot necessarily used E, is the main air blast line to the generatorduring the entire blast period, but just until with its air controlvalve at S. F, is the rich gas is being produced from air blast up runsteam line with the steam control as will be the case when heat ingenerator valve, at. T. Th? down run steam line is is sufficiently high.The gas first roduced shown at G, and its steam control valve at onblasting is always very lean. ery little U. The off-take to carbureterfor gas made auxiliary steam is used, and usually for but during an nrun is at I, and the off-take a. short time unless carbureter andsupervalve is at The down run off-take is heater are not sufiicientlyhot and more rich l\, is gas is needed to heat them, in which case theso-called hydrogen pipe which connectssuflicient steam is used toaccomplish this down run off-take with the carbureter. The end. Afterthis air blast when fuel is suflimain steam line is representedby N. Theciently hot, a down run is made by first air'pressure tank for supplyingair to theturning off air at valve S and'turning off auxiliary air linesis shown at O. P, and steam at valve W, and then admitting steam R,represent respectively the auxiliary air through the fire from abovefuel bed by lines to the top and bottom of generator, opening valve U ondown run steam line. Q. When this down run is being made, valve Theauxiliary steam line to the base of gen- 'L in off-take must be open,and valve J erator :is shown at V, with the steam conmust be closed.While this down run steam trol valve W. is on, .a small quantity of airis admitted greater, using bituminous fuel.

through the up er auxiliary air line P, by opening valve This air keepsthe fuel up to the desired heat for a longer period of steam run, thusincreasing the capacity of the water gas set. repeated except that asmall amount of auxiliary steam is used on every air blast after thefirst if conditions require it. It is necessary. on blasting with air,or making a steam run that valve L be closed and valve J be open. I Onall down runs valve J is closed and valve L is open.,

Air is nearly always supplied to the main air blast line by a fan orblower, and the air pressure procurable from such fans is usually notgreat enough to use this source of air to replace the high pressureauxiliar air which I prefer to use in my process. here would be dangerof explosion if low pressure air were used during steam runs. Forexample if a little water condensed in the steam line and was blown intothe generator as steam was turned on, the high pressure immediatelycreated would force gas back into the low pressure air line and the gasand air mixture might explode and do damage. A meter, governor be usedon this high pressure auxiliary air supply line. I also prefer to usean'auxili ary steam line separate from the regular up run steam line forsimilar safety reasons.

The auxiliary steam admitted through valve W in the figure can beregulated by a governor to give any desired-quantity or pressure, butcomingthrough avery small line there is never a possibility of a greatquantity of steam entering at once or an excessive pressure beindeveloped, and hence there is no dan er 0 back firing in blast line.

T e objects of my process are accomplished as follows:

Object 1 is accomplished by admittinga relatively small volume of airwith the steam during the runs, causing combustion to take place andthereby preventing the fuel from becoming superficially. chilled, and

simultaneously lengthening the run period. Further, object 1-isaccomplished by the proper use of up and down-runs consistent with thenew method of blasting (with the occasional use of steam during theblast) and of making the steam run (by the use of air with the steamduring therun).

- #2 is accomplished by governing the amount of auxiliary steam admittedduring the blast. The more steam admitted at this time the morecombustible gas is produced to burn in carbureter and superheater asshown in reaction #4 supra.

3 is accomplished on account of the fact that the slightly leaner watergas, which is produced in increased volume, requires more oil per givenperiod of time to carburet it. This heavier duty for the carbureter andsuperheater requires that more heat be sup- The cycle is now andpressure gage should.

plied them and thus is it possible to burn more gas in them without thedanger of overheating them.

#4 is accomplished along with #3.

#5 is accomplished by not wasting any combustible as at the stack ofsuperheater, but by burning it as mentioned in #3 on this page.

#6. The auxiliary air admitted during the gas making period prolongs thegas making period and also produces a greater volume of water gas pergiven time. This, with the additional volume of gas from the carburetingoil, gives an increased capacity to a given sized water gas set. Theadditional volume of water gas made is not due chiefly to the addedvolume of gas from the auxiliary air. The gas made in generator persecond during steam run in present practice,,is decidedly greater thefirst few seconds that the steam is admitted and then falls off.rapidly. Now, the auxiliary air used in my process during the steam run,prevents the temperature from dropping too rapidly and thus increasesconsiderably this maximum gas making period, and also the volume pergiven time. I

' #7 is accomplished due to the fact that the auxiliary steam usedduring the blast keeps the clinker zone cooler.

#8 is accomplished by the increase in amount of blast.

#9 is accomplished, due to ditions obtaining in the generator; to thebenefits derived from admitting auxiliary air during the down runs, andto the increased per cent. of high temperature fuel in generator.

The results obtained during the run with my process are vitally affectedby the method of blasting, as well as by the direction of the blast andthe amountof air per unit time. This is evident since the quality andquantity of the blue gas produced during the run depend on the conditionand temperature of the fuel, and on the volume of the fuel that isheated to a gas making temperature. am' able (by the proper use of airwith the steam during the run; with the proper proportion of up and downruns, and with the occasional, use of some steam during the blast) toobtain absolute control over the condition of the fuel inthe generator'and better fire conam thereby enabled to make the maximum amount ofhigh quality gas per unit of time during the run. By making up blastsonly being instantly heated to a high temperature has a longer time ofcontact with the fuel at a high temperature than it would where thesteam had to travel half way through the fuel bed before reaching thehighest'temperature. The zone of'com lete combustion being at the lowerpart of the fuel bed in my process causes the blue gas leaving thegenerator to leave at a lower temperature than the highest temperaturein the generator. This is particularly true on all up runs when the hotgases pass through the green fuel at the top of the generator causingdistillation of much of the volatile matter from the fuel, which isretained in the blue gas which is thereby enriched.

Since less heat is removed from the generator as sensible heat per unitof gas made, it follows that more heat isavailable for gas makingpurposes.

I That there is definite coaction between the blast and run in myprocess is further evident on considering the following: I use up blastsonly and use many up runs and some down runs, thus preventing too greata concentration of heat in a particular zone. This is adecided advantageover the processes that use a down blast only and follow them with upruns only, since in these processes a zone of intense heat is creatednear the top of the fuel bed. In such cases the generator top, off-takevalve and off-take pipe are constantly in danger, (danger of overheating and melting) due to the excessive temperature created in thishot upper zone; the blue gas leaves the generator at an excessively hightemperature thus causing an increase in the generator fuel per thousandfeetof gas made; the steam never strikes the hottest part of the fuelbed first. The ash formed during the down blasts (being near the top ofthe generator) is, to a considerable extent, carried over into thechecker chambers on subsequent runs. This ash deposit is a source ofconsiderable trouble.

In my process I make use of the commonly used carbureting methodconsistsing in blowing or spraying oil into heated checker chambers. Irecognize that this is not new and therefore do not claim patent on thatprocess as such. However I obtain a marked improvement in carburetingresults and use the old method in a new way. That is: p

(1) I make a better grade of blue gas which contains considerablevolatile matter of the fuel, thus the oil is cracked in a differentatmosphere.

(2) In using air during the run some producer gas is generated whichfurther changes the atmosphere the oil is cracked in.

'(3) Since I make more blue gas (including the volatile from the fuel,and the producer gas made) more oil is required per run with a givensize set than in other process, so far as I am aware. This, togetherwith the method of blasting allows for a more perfect control over thetemperature in the cracking chambers without the customary waste ofblast gases at the stack.

(4) The rate of production of blue gas is more uniform in my process, onaccount of the air admitted during the run and on ac count of the bettertemperature conditions obtaining in the generator, hence the oilconcentration in the cracking chambers can be maintained more uniformand the cracking more efiiciently done.

I claim:

A process for the manufacture of combustible gas by an intermittentmethod, using bituminous coal or other solid fuel containing volatilecombustible matter, consisting in first heating a bed of ignited fuel ina generator by blasting it with air, using an up blast only, frombeneath the fuel bed, and using simultaneously with this air blast arelatively small amount of steam also injected from beneath the fuel bedduring the fore part of the blast period only, for the prevention ofsmoke, prolonging said blast, so as to better heat the upper zones inthe fuel bed, shutting off said air, as well as the steam usedtherewith, and making up-anddown runs, a small quantity of air belnginjected with the steam, during each of said runs, for the purpose ofprolonging the period of said runs, and making at least two up runs toevery down run for the purpose set forth.

In testimony whereof I aflix my signature in the presence of twowitnesses.

Mrs. A. H. RAYMOND, A. H. Ramona.

